A manual starting device of an internal combustion engine generally rotates a rope reel by pulling a recoil rope and executes an engine start by transmitting the rotation of the rope reel to a crank shaft of the engine. However, in this kind of engine starting device, not only it is necessary to pull the recoil rope in a state of making a pulling speed of the recoil rope higher to some degree, but also a pulling length is long. Accordingly, it is often the case that a great aged person and a weak person can not easily start the engine. Then, the engine starting device by which even the person having a small pulling force of the recoil rope can easily start the internal combustion engine has proposed, for example, by Japanese Utility Model Application Laid-Open No. 1-91075 (patent document 1), Japanese Patent Application Laid-Open No. 2001-65435 (patent document 2) and the like.
Among them, in accordance with the engine starting device of the patent document 1, there are provided with a recoil drum around which a recoil rope is wound, a first power spring energizing in a direction of winding the recoil rope around the recoil drum, a first ratchet formed in the recoil drum, a second ratchet engaging with a second ratchet pawl provided in a crank shaft of the engine at a time of rotating in the engine starting direction, a second power spring coupled to the second ratchet and accumulating a spring force rotating the ratchet in the engine starting direction, a first ratchet pawl provided in the second ratchet, engaging with the first ratchet, transmitting the rotation of the recoil drum to the second power spring via the second ratchet, and accumulating the spring force in the power spring, and a stopper member detachably engaging with the second ratchet and inhibiting the rotation of the second ratchet generated by the spring force of the second power spring, which are arranged coaxially.
In order to start the engine by means of the starting apparatus, the stopper member is previously engaged with the second ratchet, a sufficient force is accumulated in the second power spring by pulling the recoil rope at a proper frequency so as to rotate the recoil drum, and the engagement between the stopper member and the second ratchet is detached at a time of starting the engine, thereby rotating the crank shaft by the spring force of the second power spring so as to start the engine. In the case where the spring force is accumulated in the second power spring, the power spring is only rotated, and any load from the engine is not applied. Accordingly, the small pulling force of the recoil rope is sufficient, even the weak person can easily execute the pulling operation of the recoil rope and it is possible to securely start the engine at a necessary time.
Further, the engine starting device in the patent document 2 mentioned above is provided with a power spring force accumulating mechanism, a manual rope reel accumulating a rotating force in the power spring force accumulating mechanism, a reset lever having a stopper inhibiting a rotation in an output side of the power spring force accumulating mechanism and holding the accumulated rotating force to a predetermined torque, and a transmission mechanism transmitting the accumulated rotating force to a crank shaft of an internal combustion engine at a time when the stopper is cancelled. In this case, the reset lever can be manually switched from a stop position to a free position, and can automatically start the engine on the basis of the same operation as the patent document 1 mentioned above. In other words, in accordance with the engine starting device, the stopper exists at the stop position in a steady state until the reset lever is set to the free position, thereby inhibiting the rotation in the output side of the power spring force accumulating mechanism. In this state, a sufficient accumulated force for starting the engine is stored in the power spring force accumulating mechanism by pulling the recoil rope at several times, and if the sufficient accumulated force is stored, the reset lever is automatically moved to the free position so as to start the engine at the same time. Therefore, even the weak person can easily operate the engine.
Both the patent documents 1 and 2 disclose the structure in which the force is accumulated in the power spring force accumulating mechanism by rotating the coil drum (the rope reel) on the basis of the pulling operation of the recoil rope. However, the structure, for example, disclosed in Japanese Patent No. 2573340 (patent document 3) accumulates force by rotating a power spring barrel drum of the power spring force accumulating mechanism via a ratchet mechanism in one direction on the basis of an electric power of an accumulator battery, cancels an engagement of a ratchet wheel of a rotation driven portion with a starter ratchet pawl at a time when the sufficient accumulated force for starting the engine is stored, and starts the engine by releasing the accumulated force.
Patent Document 1: Japanese Utility Model Application Laid-Open No. 1-91075
Patent Document 2: Japanese Patent Application Laid-Open No. 2001-65435
Patent Document 3: Japanese Patent No. 2573340